Mixing syringe

ABSTRACT

A mixing syringe assembly which maintains the respective constituents of a composition in separate chambers, and which includes a shuttle assembly for interconnecting the chambers for mixing the respective constituents therein prior to use.

United States Patent [72] Inventors HarveyJ.Engelsher Yonkers, N.Y.;Peter C. Hofstra, Paterson, N.J.; Robert W. McKirdy, Scarsdale, N.Y.[21] Appl. No. 767,262 [22] Filed Oct. 14, 1968 [45] Patented Mar. 16,1971 [73] Assignee Horizon Industries, Ltd.

New York, N.Y.

[54] MIXING SYRINGE 10 Claims, 8 Drawing Figs.

[52] U.S. C1 128/218 [51] Int. Cl A6lm 5/22 [50] Field ofSearch 128/215,216, 218 (P), 218 (PA), 218.1, 218.1 (P), 218.2; 128/218, 218 (M), 220,272

[56] References Cited UNITED STATES PATENTS 1,557,836 10/1925 Hein128/220 Primary Examiner-Joseph S. Reich Attorney- Irving SeidmanABSTRACT: A mixing syringe assembly which maintains the respectiveconstituents of a composition in separate chambers, and which includes ashuttle assembly for interconnecting the chambers for mixing therespective constituents therein prior to use.

MIXING sYRINcs BACKGROUND or THE INVENTION I.Field of the Invention Thisinvention relates generally to a mixing syringe, and more particularly,to a device for mixing amedicament' with a suitable diluent to form amixture suitable for'injection.-

2. Description of the Prior Art Many drugs: and medicinal products aresubject to deterioration unless they are manufactured in dry powderform, and which are brought into solution or into suspension in asuitable diluent immediately prior to use; For example, certainantibiotics, vitamins and hormones do not retain their properties whenpackaged -in' solution form. Manufacturers of such products havetherefore been required to market the powder and the diluent in separateflasks, ampuls or other receptacles, whereupon therespectiveconstituents are subsequently mixed together in a bottle. The'composition or mixture is then drawn into a syringe and administered assoon as possible to the patient, oris added to some othenparenteralsolution for immediate use. It is readily appar'entth'at the use ofseparate flasks orampuls increases the manufacturing cost. of j theproduct, increases the possibility of spilling the constituents duringthe mixing operation" and increase the possibilityof contamination ofsuch constituents during the mixing operation and during the subsequenttransferring operation of same tothesyringe j v In thisiconnection',the;mixing of certain products must be performed with extreme cautiomForexample, the mixing of nitrogen mustard, whichis used in cancer therapy,is. an ,extremely dangerous operation causing'severecaustic burns ifbrought accidentally into contact with the skin.

In an .attempLto overcome some of the problems and hazards referredtoabove, there has been proposed various syringe assemblies formed of,a.plurali ty of compartments, A

medicament is disposed in one of thecompartments anda.

diluent is disposed in another one of said compartments, whereby therespective. substances are mixed together immediately prior to use. Themajor difficulty and disadvantage. of such known syringe assembliesreside in the mixing operation of the respective substances therein. Inthis connection, it has been found that the known syringe assemblies donot provide sufficient or adequate means for effectively and efficientlymixing the respective substances prior to use.

The present invention overcomes the above difficulties and disadvantagesby providing a mixing syringe which maintains the respective substancesin separate compartments, and which includes novel shuttle means forquickly and effectively mixing said substances in a manner hereinafterdescribed.

SUMMARY or THE INVENTION plunger. for carrying selective constituentsof. a composition;

said barrel and plunger each having a piston. reciprocably. mountedtherein for defining the respective chambers. A mixing shuttle isprovided having conduitmeans mounted thereon for conjoint movement.therewith. The :barrel; plunger and mixing shuttle are connectedtogether whereby the opposite end portions of the conduit means 'arerespectivelyconnected to the barrel piston and the plunger piston forconjoint movement therewith. The end portions of the conduit means haveterminal ends respectively penetrating the pistons for establishingcommunicationbetween the respective chambers via said conduit means formixing the respective constituents therein in. response to thereciprocabie and conjoint movement of the shuttle means and the pistonsrelative to the barrel and the plunger. I g

In another embodiment of the invention, the plunger is replaced with anexpansible chamber for carrying a selected constituent of thecomposition; said chamber having a forward wall portion connected to aconduit end portion for conjoint movement therewith. In thisembodiment,. -the.end portionsof the conduit means have terminal endsrespectively penetrating the barrel piston andthe expansible chamber forestablishing communication between the respective chambers via. saidconduit means for mixing the respective constituents therein in responseto the reciprocable movement of the shuttle means and the expansion andcontraction of the expansible chamber.

Suitable outlet means are provided on the barrel for dispensing themixture oncomposition therefrom.

Accordingly, an object of the present invention is to provide a mixingsyringe for mixing a dry powdered medicinal substancewith a suitablediluent to form a mixture suitable for injection, andto provide a deviceby which the mixing and the injection can be effected successively.

The above and other objects, features and advantages of the presentinvention will become more apparent from a consideration of thefollowing detailed description when taken in conjunction with theaccompanying drawings.

BRI F DESCRIPTION or TasuR/twmos FIG. 1 is a side elevationalview, withparts in section and parts broken away, of the mixing syringe assemblyconstructed in accordance with the present invention;- 1

' FIG. 2 is a'view similar to FIG. 1 illustrating the component partscoupled together;

FIG. 3 is a view similar to FIG. 2 illustrating one position of themixing syringe assembly'during the mixing operation; and

FIG. 8 is a view similar to FIG. 7 illustrating the mixing syringe inposition for dispensing the composition therefrom.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to the drawings, andmore particularly to FIGS. 1 through 4, numeral 10, represents themixing syringe constructed in accordance withthe present invention.Syringe 10 includes a barrel 1 2 formed of glass, plastic or othersuitable material. In accordance with conventional construction, barrel12 is provided with a tubular wall 14 and a transversely extending frontwall.l6 from which a tip or nosepiece I8 projects outwardly and servesas a dispensing outlet. ln'this connection, nosepiece 18 isprovided witha bore 20 establishing communication between the interior of barrel 1 2and nosepiece 1 8. Cap 22 is separably mounted on nosepiece 18.

by suitable fastening means, indicated generally bynumeral 24;, andserves as a closure for the barrel dispensing outlet dun.

ing the mixing operation. At such time as the mixture or composition isto be dispensed from the barrel outlet, cap 22 is removed and replacedwith a conventional hypodermic needle in a manner'hereinafter described.The rear end portion of tubular wall I4 is open and is. provided with atransversely extending flange portion 26 projecting outwardly andserving as finger gripping portions for barrel l2.

Reciprocably mounted within the open end of barrel 12 is a piston 28formed of a flexible, resilient and penetrable materi-,

al such as rubber or the like. Piston 28 constitutes a cylindrical plugor seal and serves to define a forward chamber30 in barrel L2 forcarrying one constituent of a composition.

Piston 28includes a conical shape cavity portion 32 formed axiallytherein and which is tapered toward the front end 5mg, face 34 thereofto provide wall portion 36 having a reduced" thickness betweenlhe bottomor apex of cavity 32 and the frontend surface 34 of piston 28, at theaxis thereof. The rear, end surface 38 o f piston Zfi definesan annularflange 40 ing a centrally provided opening 42 therein affording accessto cavity portion 32. The. construction is such as top ermit piston 28to be separably connected to a mixing shuttle of the syringe assembly.

Mixing shuttle 44 is provided with a tubular wall 46 reciprocablymounted through the open end of barrel l2 and located rearwardly ofpiston 28. Shuttle 44 may be formed of glass, plastic or other suitablematerial. Tubular wall 46 includes a transversely extending flangeportion 48 projecting outwardly from the rear end thereof and serving asfinger gripping portions for shuttle 44. Tubular wall 46 furtherincludes a transversely extending wall portion 50 projecting radiallyinwardly from the forward end thereof and to which is fixedly securedconduit means 52 extending axially of tubular wall 46; said conduit 52having a bore 54 extending longitudinally the length thereof. Theconstruction is such that conduit 52 moves conjointly with thereciprocable movement of shuttle 44.

The end portions 56 and 58 of conduit 52 are provided with head portions60 and 62 respectively, for interconnecting various components of thesyringe assembly. In this connection, head portion 60 has a surfaceconfiguration complementary to the taper of cavity 32 in piston 28, andincludes a tapered terminal end 64 projecting forwardly therefrom. Theconstruction is such that the axis of terminal end 64 is coincident withthe axis of piston 28 for subsequently piercing wall portion 36 ofpiston 28. Accordingly, head portion 60 and terminal end 64, togetherwith piston cavity 32 and piston flange 40, provide coacting means forinterengaging the end portion 56 of conduit 52 with piston 28 uponslidable movement of conduit 52 relative to said piston. Head portion 62similarly includes a tapered terminal end 66 for interconnecting the endportion 58 of conduit 52 to a plunger component of the syringe assembly.

Reciprocably mounted within shuttle 44 is a plunger assembly indicatedgenerally by the numeral 68. Plunger 68 may be formed of glass, plasticor other suitable material, and includes a tubular wall 70telescopically disposed within shuttle 44. Tubular wall 70 is closed atthe rear end 72 thereof and may be provided with a transverselyextending flange portion 74 projecting radially outwardly therefrom andserving as finger gripping portions for plunger 68. Tubular wall 70further includes another transversely extending flange portion 76projecting radially inwardly from the forward end thereof. Reciprocablymounted within plunger 68 is a piston 78 formed of a flexible, resilientand penetrable material such as rubber or the like. Piston 78 issuitably sized to constitute a cylindrical plug or seal for defining arearward chamber 80 in plunger 68 for carrying another constituent ofthe composition. In this connection, piston 78 is similar inconstruction to piston 28, and includes a conical shape cavity portion82 formed axially therein and which is tapered toward the rear endsurface 84 thereof. Accordingly, there is provided a piston wall portion86 having a reduced thickness between the bottom or apex of cavity 82and the rear end surface 84 of piston 78, at the axis thereof. Theforward end surface 88 of piston 78 defines as annular flange 90 havinga centrally provided opening 92 therein affording access to cavityportion 82.

Referring again to mixing shuttle 44, the head portion 62 of conduit endportion 58 is provided with a surface configuration complementary to thetaper ofcavity 82 in piston 78. The construction is such that the axisof terminal end 66 of head portion 62 is coincident with the axis ofpiston 78 for subsequently piercing wall portion 86 of piston 78. It isnow apparent that head portion 62 and terminal end 66, together withpiston cavity 82 and piston flange 90, provide coacting means forinterengaging the end portion 58 of conduit 52 with piston 78 uponslidable movement of conduit 52 relative to said piston.

Having described the component parts of the novel mixing syringe of thepresent invention, attention is now directed to the operation thereof asembodied in FIGS. 1 through 4. Chambers 30 and 80, located in barrel 12and plunger 68 respectively, are illustrated as carrying theconstituents of the composition. It will be appreciated that whilechamber 80 is illustrated as carrying the dry powder medicament andchamber 30 carrying the suitable diluent, the location of the respectiveconstituents with respect to said chambers can be reversed. Furthermore,it is readily apparent that the syringe of the present invention can beused for mixing medicinal products which do not include a powderconstituent. In those situations where one of the constituents is inpowder form, it is preferable to connect the mixing shuttle to thechamber carrying the dry constituent prior to connecting the mixingshuttle to the chamber carrying the diluent.

Accordingly, shuttle 44 and plunger 68 are slidably moved relative toone another for interengaging conduit end portion 58 with piston 78,whereby piston cavity 82 receives the head portion 62 of conduit 52. Thearrangement is such that terminal end 66 of conduit 52 pierces pistonwall portion 86 for establishing communication between chamber and thebore 54 of conduit 52. The sealing arrangement of piston 78 relative toplunger wall 70, and the thickness of piston wall portion 86, are suchthat coupling of conduit end portion 58 with piston 78 is readilyachieved without materially displacing the piston within plunger wall70; whereupon piston 78 will thereafter move conjointly with conduit endportion 58. Mixing shuttle 44 is then connected to chamber 30 byslidably moving shuttle 44 and barrel 12 relative to one another forinterengaging conduit end portion 56 with piston 28. The couplingarrangement is similar to that described with respect to chamber 80whereby piston cavity 32 receives the head portion 60 of conduit 52, andterminal end 64 of conduit 52 pierces piston wall portion 36 forestablishing communication between chamber 30 and the bore 54 of conduit52. It will be noted that during the coupling operations describedabove, the piston flanges 40 and 9,0 ofpistons 28 and 78 respectively,must be sufficiently resilient so as to be initially displaced withinthe respective piston cavities 32 and 82 and thereafter reassume theirnormal positions whereby said flanges 40 and will abut against therespective shoulders of conduit head portions 60 and 62. In thisconnection, FIG. 1 illustrates in phantom conduit end portion 56 afterit has been slidably moved within barrel 12 a distance sufficient topermit piston flange 40 to reassume its normal position. It is nowapparent that communication is established between chambers 30 and 80via bore 54 of conduit 52 for mixing the respective constituents of thecomposition therein in response to the reciprocable and conjointmovement of shuttle 44 and pistons 28 and 78 relative to barrel 12 andplunger 68. In other words, when barrel l2 and plunger 68 are fixedlyheld in the position illustrated in FIG. 3, forward movement of shuttle44 will force the diluent in chamber 30 through the bore 54 of conduit52 and into contact with the powder medicament in chamber 80.Thereafter, retracted movement of shuttle 44 will force the mixedconstituents from chamber 80 to chamber 30 via conduit 52. Furtherreciprocable movement of shuttle 44 will transfer the mixed constituentsalternately between the respective chambers for quickly and effectivelymixing said constituents prior to use. Flange portion 76 of plunger 68serves as a stop to prevent piston 78 from being inadvertently withdrawnfrom plunger 68 during the mixing operation. After the constituents havebeen sufficiently mixed, shuttle 44 is positioned to locate the mixtureor composition in chamber 80. Barrel closure cap 22 may now be removedfor mounting the hub 94 of hypodermic needle 96 on barrel nose piece 18in a conventional manner. Mixing shuttle 44 can now be positioned tolocate the composition in chamber 30, as shown in FIG. 4, whereby thecomposition will be dispensed from the barrel outlet and throughhypodermic needle 96 in response to the combined forward movement ofplunger 68 and shuttle 44 relative to barrel 12.

FIGS. 5 through 8 represent another embodiment of a mixing syringe 100constructed in accordance with the present invention wherein plunger 68is replaced with an expansiblc chamber for carrying a selectedconstituent of the composition. In this connection, the structuraldetails of the respective syringes l0 and 100 are essentially similar toone another, and accordingly, those details of syringe 100 common tosyringe carry similar reference numerals designated with a primenotation; said common details and components operating and functioningin a similar manner so that a detailed description of same is not deemednecessary.

Expansible chamber 110 has a forward wall portion 112 slidably mountedwithin shuttle M'and an axially extensible wall portion 114 extendingrearwardly thereof which is closed by rear wall portion 116. Expansiblechamber 110 may be formed of a flexible, resilient material such asrubber, plastic or the like, and constitutes a bellows which defineschamber 118 for carrying the powder medicament. In the preferredconstruction, forward wall portion 112 is formed of a penetrablematerial, such as rubber, and includes a conical shape cavity portion120 formed axially therein and which is tapered toward the rear endsurface 122 thereof. Accordingly, there is provided a wall portion 124having a reduced thickness between the bottom or apex of cavity 120 andthe rear end surface 122, at the axis thereof. The forward end surface126 of forward wall portion 112 defines an annular flange 128 having acentrally provided opening 130 therein affording access to cavityportion 120.

Referring to mixing shuttle 44'the head portion 62'of conduit endportion 58' is provided with a surface configuration complementary tothe taper of cavity 120 in forward wall portion 112. The construction issuch that the axis of terminal end 66' of head portion 62 is coincidentwith the axis of expansible chamber 110 for subsequently piercing wallportion 124 of forward wall portion 112. It is now apparent that headportion 62' arid terminal end 66', together with forward wall cavity 120and forward wall flange 128,.provide coacting means for interengagingthe end portion 58with the forward wall portion 112 of expansiblechamber 110, and piercing wall portion 124 upon slidable movement offorward wall portion 112 relative to conduit 52.

in operation, shuttle 44' and the forward wall portion 112 of expansiblechamber 110 are slidably moved relative to one another for interengagingconduit end portion 58' with forward wall portion 112, whereby forwardwall cavity 120 receives the head portion 62' of conduit 52'. Thearrangement is such that terminal end 66' of conduit 52' pierces wallportion 124 for establishing communication between chamber 118 and thebore 54' of conduit 52. The coupling operation is similar to thatdescribed with respect to the embodiment of FIGS. 1 through 4 wherebythe forward wall portion 112 of expansible chamber 110 will thereaftermove conjointly with conduit 0 PORTION 58' Mixing shuttle 44 is thenconnected to chamber 30 by slidably moving shuttle 44' and barrel 12'relative to one another for interengaging conduit end portion 56' withpiston 28' in the manner heretofore described. It is now apparent thatcommunication is established between chambers 30' and 118 via bore 54 ofconduit 52' for mixing the respective constituents of the compositiontherein in response to the reciprocable movement of shuttle 44' and theexpansion and contraction of expansible chamber 110. In other words,piston 28' and the forward wall portion 112 of expansible chamber 110are coupled to conduit end portions 56' and 58' respectively, forconjoint movement therewith. Forward movement of shuttle 14' relative tobarrel 12', as shown in FIG. 7, will force the diluent in chamber 30'through the bore 54' of conduit 52' and into contact with the powdermedicament in chamber 118 thereby expanding expansible chamber 110.Thereafter, retracted movement of shuttle 44 relative to barrel 12 willreduce the pressure in chamber 30' and thus serve to transfer the mixedconstituents from chamber 11% to chamber 30', via conduit 52', therebycontracting expansible chamber 110. Furtherreciprocable movement ofshuttle 44' will transfer the mixed constituents alternately between therespective chambers for quickly and effectively mixing said constituentsprior to use. The dispensing operation is performed similarly to thatdescribed with respect to the embodiment of FlGS. 1 through 4, wherebyshuttle 44' is positioned to locate the mixture or composition inchamber 118. Barrel closure cap 22' may now be removed for mounting thehub 94 of hypodermic needle 96 on barrel nose piece 18. Mixing shuttle44 is then positioned to locate the composition in chamber 30', as shownin H6. 8, whereby the composition will be dispensed from the barreloutlet and through hypodermic needle 96 in response to the combinedforward movement of expansible camber and shuttle 44 relative to barrel12'.

Accrodingly, there is now provided a mixing syringe assembly whichmaintains the respective constituents in separate compartments and whichincludes a shuttle assembly for interconnecting the compartments forquickly and effectively mixing the constituents prior to use. Plunger 68and expansible chamber 110, respectively containing selectedconstituents, can be manufactured, supplied and stored separately forselective use and coupling with the mixing syringe as required.Furthermore, whereas the forward wall portion 112 of expansible chamber110 is preferably illustrated as being slidably mounted within shuttle44', this construction is merely illustrative and is not to be deemed alimitation on the invention. For example, the embodiment of FIGS. 5through 8 can be readily constructed with conduit end portion 58'extending beyond the open end ofshuttle 44' and being connected to theforward wall portion 112 of expansible chamber 110 in the mannerheretofore described, without otherwise altering the mixing anddispensin operation. if desired, the mixed constituents can be added tosome other parenteral solution for immediate use.

While specific embodiments of the invention have been shown anddescribed in detail, it will be readily understood and appreciated thatvarious changes or modifications thereof may be made without departingfrom the spirit and scope of the invention as set forth in the appendedclaims.

We claim: 1

1. A string for mixing the constituents of a given composition anddispensing the same comprising:

a. a barrel having a dispensing outlet at a forward end thereof andbeing open at the rear end thereof;

b. closure means separably mounted on the outlet end of the barrel;

c. piston means reciprocably mounted within the barrel and defining achamber forwardly thereof for containing one constituent of thecomposition;

. shuttle means mounted within the barrel for reciprocable movementtherein;

e. movable chamber means in said piston means for containing anotherconstituent of the composition;

f. said shuttle means including conduit means arranged for conjointmovement therewith;

g. said conduit means having one end portion engaged with and projectingthrough a wall portion of the movable chamber means; and

h. the other end portion the said conduit means being engaged with andprojecting through the piston means whereby said conduit means is incommunication between the first and second mentioned chambers via saidconduit means for alternately and forcibly reversing the flow of theconstituents of the composition between said chambers for mixing saidconstituents in response to selective reciprocal movement of the shuttlemeans relative to the barrel and he movable chamber means; and wherebythe composition may be dispensed from the barrel outlet upon removal ofthe closure means therefrom and in response to the combined forwardmovement of the shuttle means and the movable chamber means relative tothe barrel.

2. A string as recited in claim 1, wherein said shuttle means comprisesa tubular member reciprocably mounted within the barrel, said tubularmember including a transverse wall portion; said conduit means extendingaxially of the tubular member and being fixed to the transverse wallportion and said other end portion of said conduit means extendingthrough and projecting beyond said transverse wall portion.

3. The syringe as recited in claim 1 wherein said movable chamber meanscomprises a hollow plunger closed at the rear end thereof and being openat the forward end thereof; second piston means reciprocably mountedwithin the plunger for defining a chamber rearwardly thereof forcontaining said other constituent of the composition; said plunger beingmounted within the shuttle means for reciprocable movement therewith.

4. A syringe as recited in claim 3, wherein said plunger includes stopmeans engageable with the second piston means for limiting the rearwardmovement of said plunger relative to the shuttle means.

5. A syringe as recited in claim 3, further comprising coacting means oneach of the first and second piston means and the opposite end portionsof said conduit means for interlocking the pistons with the respectiveend portions of said conduit means and connecting said pistons to saidconduit means for conjoint movement therewith, whereby the terminal endsof said end portions respectively penetrate a wall portion of itsassociated piston means.

6. A syringe as recited in claim 5, wherein said coacting means compriseenlarged head portions on the opposite end portions of said conduitmeans; said coacting means of said first and second piston meansincluding cavity means for respectively receiving the head portions ofsaid conduit means.

7. A syringe as recited in claim 6, wherein the cavity means in eachpiston means is formed in one end surface thereof and is tapered towardthe other end surface thereof to thereby provide a portion of relativelyreduced thickness of said piston between the forward portion of saidcavity means and the other end surface of said piston at the axisthereof; each of the head portions of said conduit means having asurface portion complementary to the taper of the cavity portion of theassociated piston means; the conduit means also having terminal endsprojecting beyond said head portions; and the axes of said terminal endsbeing respectively coincident with the axes of said first and secondpiston means.

8. A syringe as recited in claim 1, wherein said shuttle means has arelatively nlargd end portion and said movable chamber means isexpansible and includes a forward wall portion and an axially extensiblewall portion extending therefrom; the forward wall portion of saidexpansible chamber means being slidably mounted within the relativelyenlarged end portion of said shuttle means.

9. A syringe as recited in claim 8, further comprising coacting means onthe rear end portion of the conduit means and the forward wall portionof the expansible chamber for interlocking the conduit means with theforward wall portion of the expansible chamber and extending rearwardlybeyond said forward wall portion.

10. A syringe as recited in claim 9, further comprising coacting meanson the forward end portion of the conduit means and the piston means forinterlocking the conduit means with the piston means extending forwardlybeyond said piston means.

1. A syringe for mixing the constituents of a given composition anddispensing the same comprising: a. a barrel having a dispensing outletat a forward end thereof and being open at the rear end thereof; b.closure means separably mounted on the outlet end of the barrel; c.piston means reciprocably mounted within the barrel and defining achamber forwardly thereof for containing one constituent of thecomposition; d. shuttle means mounted within the barrel for reciprocablemovement therein; e. movable chamber means in said piston means forcontaining another constituent of the composition; f. said shuttle meansincluding conduit means arranged for conjoint movement therewith; g.said conduit means having one end portion engaged with and projectingthrough a wall portion of the movable chamber means; and h. the otherend portion the said conduit means being engaged with and projectingthrough the piston means; whereby said conduit means is in communicationbetween the first and second mentioned chambers via said conduit meansfor alternately and forcibly reversing the flow of the constituents ofthe composition between said chambers for mixing said constituents inresponse to selective reciprocal movement of the shuttle means relativeto the barrel and the movable chamber means; and whereby the compositionmay be dispensed from the barrel outlet upon removal of the closuremeans therefrom and in response to the combined forward movement of theshuttle means and the movable chamber means relative to the barrel.
 2. Asyringe as recited in claim 1, wherein said shuttle means comprises atubular member reciprocably mounted within the barrel, said tubularmember including a transverse wall portion; said conduit means extendingaxially of the tubular member and being fixed to the transverse wallportion and said other end portion of said conduit means extendingthrough and projecting beyond said transverse wall portion.
 3. Thesyringe as recited in claim 1 wherein said movable chamber meanscomprises a hollow plunger closed at the rear end thereof and being openat the forward end thereof; second piston means reciprocably mountedwithin the plunger for defining a chamber rearwardly thereof forcontaining said other constituent of the composition; said plunger beingmounted within the shuttle means for reciprocable movement therewith. 4.A syringe as recited in claim 3, wherein said plunger includes stopmeans engageable with the second piston means for limiting the rearwardmovement of said plunger relative to the shuttle means.
 5. A syringe asrecited in claim 3, further comprising coacting means on each of thefirst and second piston means and the opposite end portions of saidconduit means for interlocking the pistons with the respective endportions of said conduit means and connecting said pistons to saidconduit means for conjoint movement therewith, whereby the terminal endsof said end portions respectively penetrate a wall portion of itsassociated piston means.
 6. A syringe as recited in claim 5, whereinsaid coacting means comprise enlarged head portions on the opposite endportions of said conduit means; said coacting means of said first andsecond piston means including cavity means for respectively receivingthe head portions of said conduit means.
 7. A syringe as recited inclaim 6, wherein the cavity means in each piston means is formed in oneend surface thereof and is tapered toward the other end surface thereofto thereby provide a portion of relatively reduced thickness of saidpiston between the forward portion of said cavity means and the otherend surface of said piston at the axis thereof; each of the headportions of said conduit means having a surface portion complementary tothe taper of the cavity portion of the associated piston means; theconduit means also havIng terminal ends projecting beyond said headportions; and the axes of said terminal ends being respectivelycoincident with the axes of said first and second piston means.
 8. Asyringe as recited in claim 1, wherein said shuttle means has arelatively enlarged end portion and said movable chamber means isexpansible and includes a forward wall portion and an axially extensiblewall portion extending therefrom; the forward wall portion of saidexpansible chamber means being slidably mounted within the relativelyenlarged end portion of said shuttle means.
 9. A syringe as recited inclaim 8, further comprising coacting means on the rear end portion ofthe conduit means and the forward wall portion of the expansible chamberfor interlocking the conduit means with the forward wall portion of theexpansible chamber and extending rearwardly beyond said forward wallportion.
 10. A syringe as recited in claim 9, further comprisingcoacting means on the forward end portion of the conduit means and thepiston means for interlocking the conduit means with the piston meansextending forwardly beyond said piston means.